#pragma once

#include <iostream>
#include <vector>
#include <string>
#include <queue>
#include <pthread.h>
#include <unistd.h>

struct ThreadInfo
{
    pthread_t tid;
    std::string name;
};

static const int defalutnum = 5;

template<class T>
class ThreadPool
{
public:
    void Lock()
    {
        pthread_mutex_lock(&mutex_);
    }
    void Unlock()
    {
        pthread_mutex_unlock(&mutex_);
    }
    void Wakeup()
    {
        pthread_cond_signal(&cond_);
    }
    void ThreadSleep()
    {
        pthread_cond_wait(&cond_,&mutex_);
    }
    bool IsQueueEmpty()
    {
        return tasks_.empty();
    }
    std::string GetThreadName(pthread_t tid)
    {
        for(const auto &ti:threads_)
        {
            if(ti.tid == tid)
                return ti.name;
        }
        return "None";
    }
public:
    static void *HandlerTask(void *args)
    {
        ThreadPool<T> *tp = static_cast<ThreadPool<T>*>(args);
        std::string name = tp->GetThreadName(pthread_self());
        while(true)
        {
            tp->Lock();
            while(tp->IsQueueEmpty())
            {
                tp->ThreadSleep();
            }
            T t = tp->Pop();
            tp->Unlock();

            t();
            std::cout << name << " run, "
                     << "result: " << t.GetResult() << std::endl;
        }
    }
    void Start()
    {
        int num = threads_.size();
        for(int i=0;i<num;i++)
        {
            threads_[i].name = "thread-"+std::to_string(i+1);
            pthread_create(&(threads_[i].tid),nullptr,HandlerTask,this);
        }
    }
    T Pop()
    {
        T t = task_.front();
        task_.pop();
        return t;
    }
    void Push(const T &t)
    {
        Lock();
        task_.push(t);
        Wakeup();
        Unlock();
    }
    static ThreadPool<T> *GetInstance()
    {
        if(nullptr == tp_)
        {
            pthread_mutex_lock(&lock_);
            if(nullptr == tp_)
            {
                std::cout << "log: singleton create done first!" << std::endl;
                tp_ = new ThreadPool<T>();
            }
            pthread_mutex_unlock(&lock);
        }
        return tp_;
    }
private:
    ThreadPool(int num = defalutnum)
        :threads_(num)
    {
        pthread_mutex_init(&mutex,nullptr);
        pthread_cond_init(&cond,nullptr);
    }
    ~ThreadPool()
    {
        pthread_mutex_destroy(&mutex_);
        pthread_cond_destroy(&cond_);
    }
    ThreadPool(const ThreadPool<T> &) = delete;
    const ThreadPool<T> &operator=(const ThreadPool<T> &) = delete;
private:
    std::vector<ThreadInfo> threads_;
    std::queue<T> task_;

    pthread_mutex_t mutex_;
    pthread_cond_t cond_;

    static ThreadPool<T> *tp_;
    static pthread_mutex_t lock_;
public:
};
template <class T>
ThreadPool<T> *ThreadPool<T>::tp_ = nullptr;

template <class T>
pthread_mutex_t ThreadPool<T>::lock_ = PTHREAD_MUTEX_INITIALIZER;